Each of a plurality of devices constituting a general communication system has a plurality of physical lines (hereinafter, referred to “lanes”) for input and output of data between the same. In addition, the devices each may adjust the number of lanes to be used according to the amount of data to be transmitted. For example, one of the devices, which operate in a power saving mode, may transmit and receive data using some of the lanes. In addition, another of the devices, which operates in a normal mode, may transmit and receive data using all of the lanes.
At this time, as the number of devices that are connected to the lanes of a single device increases, a data transmission rate of each lane decreases, whereas the total amount of transmission data of the device increases. At this time, the increased amount of transmission data is considerably limited. Furthermore, in the case where the data transmission between the devices is made sporadically, if the number of devices is increased, the data transmission rate of each lane tends to decrease as well.
Therefore, a lane operation method of the device, by which the amount of transmission data can be increased without a decrease in the data transmission rate, is required.